摘要 | 以全营养处理为对照,设计缺氮和缺磷2种缺素处理,分析不同营养条件下凤眼蓝〔Eichhornia crassipes (Mart.) Solms〕形态、光合作用、抗氧化系统、氮含量、磷含量及根际微生物群落的变化。结果显示:总体上看,缺氮和缺磷处理可显著抑制凤眼蓝鲜质量、叶数、叶宽、分株数和匍匐茎总长,减弱叶发育,增强根发育,且缺磷处理对植株生长和繁殖的抑制作用更明显;缺氮和缺磷处理可显著抑制凤眼蓝叶片的净光合速率和气孔导度,缺氮处理可显著降低叶片叶绿素相对含量,缺氮处理对凤眼蓝叶片光合作用的抑制效果强于缺磷处理。缺磷处理使凤眼蓝叶片中过氧化氢酶、过氧化物酶和超氧化物歧化酶活性以及丙二醛含量明显上升,而缺氮处理对叶片和根中上述3种酶活性和丙二醛含量总体无明显影响。缺氮和缺磷处理使凤眼蓝叶片中氮、磷含量降低,且氮、磷元素优先分配向根部,缺磷处理引起的磷含量的降幅明显高于缺氮处理引起的氮含量的降幅。缺氮和缺磷处理使凤眼蓝根际微生物群落组成多样性降低,其中氮代谢相关(硝酸盐还原、固氮、氮呼吸和硝酸盐呼吸)微生物的相对丰度显著降低,且在氮元素充足时,缺乏磷元素会降低凤眼蓝根际氮代谢相关微生物的富集。综合研究结果显示:缺氮和缺磷处理均能通过抑制光合作用、限制氮代谢相关微生物富集等方式抑制凤眼蓝生长和繁殖,且缺磷处理对凤眼蓝产生的非生物胁迫更强、对凤眼蓝生长的抑制作用更显著。通过控制凤眼蓝对磷元素的吸收防控凤眼蓝爆发具有较大的应用潜力。 |
Abstract | Taking total nutrient treatment as the control, two nutrient deficiency treatments namely nitrogen deficiency and phosphorus deficiency were employed, and the variations of morphology, photosynthesis, antioxidant system, nitrogen content, phosphorus content, and rhizosphere microbial community of Eichhornia crassipes (Mart.) Solms under different nutritional conditions were analyzed. The results show that in general, nitrogen deficiency and phosphorus deficiency treatments can significantly inhibit the fresh mass, leaf number, leaf width, ramet number, and stolon total length of E. crassipes, impair leaf development, enhance root development, and phosphorus deficiency treatment has more evident inhibitory effect on plant growth and propagation; nitrogen deficiency and phosphorus deficiency treatments can significantly inhibit net photosynthetic rate and stomatal conductance of leaves of E. crassipes, nitrogen deficiency treatment can significantly decrease leaf chlorophyll relative content, and the inhibitory effect of nitrogen deficiency treatment on leaf photosynthesis of E. crassipes is stronger than that of phosphorus deficiency treatment. Phosphorus deficiency treatment evidently increases activities of catalase, peroxidase, and superoxide dismutase and malondialdehyde content in leaves of E. crassipes, while nitrogen deficiency treatment generally has no evident effect on above three enzyme activities and malondialdehyde contents in leaves and roots. Nitrogen deficiency and phosphorus deficiency treatments can cause decrease of contents of nitrogen and phosphorus in leaves of E. crassipes, and nitrogen and phosphorus elements are preferentially allocated to root, and the decrement of phosphorus content caused by phosphorus deficiency treatment is evidently higher than that of nitrogen content caused by nitrogen deficiency treatment. Nitrogen deficiency and phosphorus deficiency treatments can cause decrease of diversity of rhizosphere microbial community composition of E. crassipes, in which, the relative abundance of nitrogen metabolism-related (nitrate reduction, nitrogen fixation, nitrogen respiration, and nitrate respiration) microorganisms significantly decrease, and when nitrogen element is sufficient, phosphorus element deficiency can decrease the enrichment of rhizosphere nitrogen metabolism-related microorganisms of E. crassipes. It is suggested that nitrogen deficiency and phosphorus deficiency treatments can both inhibit the growth and propagation of E. crassipes by the ways including inhibition of photosynthesis and limitation of enrichment of nitrogen metabolism-related microorganisms, and phosphorus deficiency treatment causes stronger abiotic stress to E. crassipes, and has more evident inhibitory effect on growth of E. crassipes. It has a great application potential to prevent and control the outbreak of E. crassipes by the way of controlling phosphorus element absorption of E. crassipes. |
关键词 | 凤眼蓝; 营养元素; 根际微生物; 生物多样性; 生物安全 |
Key words | Eichhornia crassipes (Mart.) Solms; nutrient element; rhizosphere microorganism; biodiversity; biosecurity |
作者 | 刘芳宇1,2a,2b, 孙林鹤2a,2b, 常雅军2a,2b, 刘吉祥2a,2b, 刘晓静2a,2b, 徐迎春1, 姚东瑞2a,2b |
所在单位 | 1. 南京农业大学园艺学院, 江苏 南京 210095; 2. 江苏省中国科学院植物研究所(南京中山植物园): a. 江苏省水生植物资源与水环境修复工程研究中心, b. 江苏省植物资源研究与利用重点实验室, 江苏 南京 210014 |
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下载次数 | 451 |
基金项目 | 国家重点研发计划专项(2022YFC2601302); 江苏省六大人才高峰高层次创新人才团队项目(TD-JNHB-008) |